Warning: This is the manual of the legacy Guile 2.2 series. You may want to read the manual of the current stable series instead.

7.2.11.1 Network Address Conversion

This section describes procedures which convert internet addresses between numeric and string formats.

IPv4 Address Conversion

An IPv4 Internet address is a 4-byte value, represented in Guile as an integer in host byte order, so that say “0.0.0.1” is 1, or “1.0.0.0” is 16777216.

Some underlying C functions use network byte order for addresses, Guile converts as necessary so that at the Scheme level its host byte order everywhere.

Variable: INADDR_ANY

For a server, this can be used with bind (see Network Sockets and Communication) to allow connections from any interface on the machine.

Variable: INADDR_BROADCAST

The broadcast address on the local network.

Variable: INADDR_LOOPBACK

The address of the local host using the loopback device, ie. ‘127.0.0.1’.

Scheme Procedure: inet-netof address

C Function: scm_inet_netof (address)

Return the network number part of the given IPv4 Internet address. E.g.,

(inet-netof 2130706433) ⇒ 127

Scheme Procedure: inet-lnaof address

C Function: scm_lnaof (address)

Return the local-address-with-network part of the given IPv4 Internet address, using the obsolete class A/B/C system. E.g.,

(inet-lnaof 2130706433) ⇒ 1

Scheme Procedure: inet-makeaddr net lna

C Function: scm_inet_makeaddr (net, lna)

Make an IPv4 Internet address by combining the network number net with the local-address-within-network number lna. E.g.,

(inet-makeaddr 127 1) ⇒ 2130706433

IPv6 Address Conversion

An IPv6 Internet address is a 16-byte value, represented in Guile as an integer in host byte order, so that say “::1” is 1.

Scheme Procedure: inet-ntop family address

C Function: scm_inet_ntop (family, address)

Convert a network address from an integer to a printable string. family can be AF_INET or AF_INET6. E.g.,

(inet-ntop AF_INET 2130706433) ⇒ "127.0.0.1"
(inet-ntop AF_INET6 (- (expt 2 128) 1))
  ⇒ "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff"

Scheme Procedure: inet-pton family address

C Function: scm_inet_pton (family, address)

Convert a string containing a printable network address to an integer address. family can be AF_INET or AF_INET6. E.g.,

(inet-pton AF_INET "127.0.0.1") ⇒ 2130706433
(inet-pton AF_INET6 "::1") ⇒ 1